As described in Applicant's issued U.S. Pat. No. 8,659,293 issued Feb. 25, 2014 and incorporated herein by reference, in the oil and gas industry, it is desirable for producers of heavy crude oil and bitumen, and in particular during cyclic steam stimulation (CSS), steam assisted gravity drainage (SAGD) and thermal assisted gravity drainage (TAGD) operations, to obtain accurate measurements of the percentage of water contained in a produced emulsion flow of oil, water and gas.
Generally, it is desired to have this measurement taken on a regular basis from the piping infrastructure near the production wells where the fluid stream is under considerable pressure and temperature. As is known, typical pressures in a SAGD operation can be in the range of 100 to 600 psi (690 kPa to 4140 kPa) or greater and temperatures can be upwards of 400° F. (204° C.) and higher. As a result, piping and control systems engineered for these environments are robust which can make the continuous monitoring of the contents within the piping relatively difficult due to the temperatures and pressures within the piping that can prevent the use of various types of sensing/monitoring equipment.
It is known, that nuclear magnetic resonance (NMR) technology can accurately and quickly measure the relative amounts of oil, water and gas in an encapsulated sample of fluid. It is also known that in order to enable NMR systems to operate within such an environment, the container holding a sample of fluid must be made of nonmagnetic material. The nonmagnetic material may be a non-metallic material.
In general, conventional pipes used to convey hydrocarbon fluids from wells have a magnetic component to them. As magnetic pipes create problems for nuclear magnetic resonance (NMR) measurement systems, the use of NMR requires specialized piping systems that enable NMR systems to operate. That is, as is known, NMR systems function by applying an external static magnetic and a pulsating electromagnetic field to a sample to determine the components of the sample in terms of water, oil and gas content. Various NMR systems are described in US Patent Publication No. 2009/0128144; US Patent Publication No. 2009/0072825; U.S. Pat. No. 6,346,813; U.S. Pat. No. 7,463,027; US Patent Publication No. 2010/0001730; and U.S. Pat. No. 6,825,657.
As NMR systems use magnetic fields, any magnetic materials located inside or near the magnetic field will damage the homogeneity of the magnetic field and undermine the accuracy and sensitivity of the NMR system. As such, there is generally a need for systems that mitigate these problems, and more specifically there has been a need for improved pipe designs that can be used with an NMR metering tool or system to increase the accuracy and sensitivity of an NMR meter in the field.